• The Transactions of the Korean Institute of Power Electronics
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• v.24 no.5
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• pp.342-348
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• 2019

The emergency power supplies (EPSs) are required to increase battery sizing for protecting power source loss above designed criteria. This study proposes a sizing method for lithium-based batteries for EPSs in nuclear power plants on the basis of the calculation method for the required energy under variable conditions. The variable conditions are related with the characteristics of lithium-based batteries, such as the temperature of the location of EPS installation, aging, and design margin. The usage of lithium-based battery reduces the cost and installation space and enables the safe and long-term supply of power compared with the use of lead-acid battery.

• Industrial Engineering and Management Systems
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• v.8 no.4
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• pp.213-220
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• 2009

A revenue sharing contract is one of the mechanisms that coordinate decision makers in a decentralized supply chain toward the consensual goal. The transfer prices between different echelons in the supply chain influence the total supply chain profits. The study aims to explore various transfer pricing heuristics on the supply chain coordination in terms of the supply chain profits and their interactions with the revenue sharing rate. A model is proposed for formulating the collaborative production and distribution planning in a decentralized supply chain with the revenue sharing mechanism. Experiment results indicate that the transfer price and the revenue sharing rate affect significantly the coordination. Among the studied pricing heuristics, the variable-cost pricing method led to the best SC profits. Raising the revenue sharing rate reduced the SC profits no matter what heuristics were employed. Furthermore, the experiments provide us clues for finding the optimal transfer price for the supply chain.

• Journal of Digital Convergence
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• v.11 no.2
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• pp.175-182
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• 2013

In this paper, the simulation model of house price is presented on the basis of pricing mechanism between the demand and the supply of apartments in seoul. The algorithm of house price simulation model for calculating the rate of price over time includes feedback control theory. The feedback control theory consists of stock variable, flow variable, auxiliary variable and constant variable. We suggest that the future price of apartment is simulated using mutual interaction variables which are demand, supply, price and parameters among them. In this paper we considers three items which include the behavior of apartment price index, the size of demand and supply, and the forecasting of the apartment price in the future economic scenarios. The proposed price simulation model could be used in public needs for developing a house price regulation policy using financial and non-financial aids. And the quantitative simulation model is to be applied in practice with more specific real data and Powersim Software modeling tool.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.125-131
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• 1995

Pneumatic System has been mainly used as main equipment for actuation and control of fluid force in manufacturing industry. For velocity control of piston, meter-out restriction method is used in many cases. In this systems, meter-out restriction method is adopted for analysing the Dynamic Charging and Discharging Process which is Variable Volume Chamber. Experiments has been conducted for different supply pressure condition. As a experimental result, charge side chamber pressure rises to supply pressure rapidily and discharge side chamber pressure decreases. Also, when the air in the cylinder is discharged, tempdrature of air decreases steeply. Restriction of the Cylinder sometimes freeze and it dose not function. The result will be useful for the analysis of pneumatic system.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.545-546
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• 2006

A problem of oil supply for a reciprocating compressor is very significant for an evaluation of reliability. Since a rotational motion of a crank shaft for the reciprocating compressor with small capacity is used for a power source of oil supply, a centrifugal force of the rotational shaft provides a stroke of oil inside the shaft like a centrifugal pump. The pumped oil rises following an inner wall and provided to a bearing passed through an oil supply hole at the side of the shaft for lubrication of the bearing. In this study, the amount of oil supply has been investigated by a numerical analysis for various conditions such as a shape of a groove, rpm of the compressor, and a shape of a flow channel. Also, a method of increasing oil supply for a low rpm has been studied so that the function can be improved for a variable condition.

• Proceedings of the KIEE Conference
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• 2003.10b
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• pp.45-47
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• 2003

This paper presents the design results and characteristics analysis of SRM for vehicle power supply. For Adaptable design of the SRM, Variable design parameters, such as stator and rotor laminations, winding details, pole numbers, and pole arcs, phases numbers are required. So, in this paper the SRM design results and the comparison of characteristics for vehicle power supply as phases changed are described.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.181-183
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• 1994

This paper presented the developments and operations of control system for Inverter-controlled air pressure type water-supply systems. The developed controller that enables regular speed and variable speed. In addition, an air supplement control system was developed to establish a utility model of water supply facility system as well as a method to optimize its operation.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.1030-1034
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• 1993

A converter topology which is capable of four-quadrant(motoring and generation) operation is proposed for the variable speed constant frequency(hereafter referred as VSCF) power conversion scheme. The new converter topology for the VSCF power conversion scheme is made of two functional stages. One is converting stage which consists of six switches and six diodes and it interfaces a three-phase 60Hz at supply and a single-phase variable-frequency ac source. The other is the commutating stage though which each phase-winding is energized.

• Journal of Society of Preventive Korean Medicine
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• v.8 no.2
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• pp.1-12
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• 2004

This paper estimated the demand and supply of physicians for oriental medicine for the period of $2009{\sim}2019$. Two equation models were used in the estimation of manpower. In 2004, the total number of physicians of oriental medicine was amounted to 13,662 registered and 10,532 available in clinical practice, respectively. According to estimates in the study, overall excess supply of physician manpower in oriental medicine was expected in the period, such as $5,300{\sim}5,700$ persons in 2009 and $900{\sim}1,700$ persons in 2019. However, the excess supply would be mitigated after 2019 mainly due to an increase in demand for oriental medical services. Specially, opening medical service market to overseas could be an exogenous variable in physician supply. An alternative manpower policy for oriental medical doctors is needed in a way of controlling oversupply.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.167-173
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• 2003

For the measurement of mass flow rate at a wide range of operation conditions, it is required that the critical nozzle gas different diameters, since the mass flow rate through the critical nozzle depends on the nozzle supply conditions and the nozzle throat diameter. In the present study, both computational and experimental investigations are performed to explore the variable critical nozzle. Computational work using the 2-dimensional, axisymmetric, compressible Navier-Stokes equations are carried out to simulate the gas flow through variable critical nozzle. In experimnet, a cylinder with several different diameters is inserted into the critical nozzle to vary the nozzle throat diameter. Computational results are compared with the experimented ones. The computed results are in close agreement with experiment. It is found that the displacement and momentum thickness of variable critical nozzle are given as a function of Reynolds numbers. The discharge coefficient of the variable critical nozzle is predicted using an empirical equation.